From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 21932 invoked by alias); 21 May 2003 16:58:23 -0000 Mailing-List: contact gdb-patches-help@sources.redhat.com; run by ezmlm Precedence: bulk List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sources.redhat.com Received: (qmail 21887 invoked from network); 21 May 2003 16:58:22 -0000 Received: from unknown (HELO crack.them.org) (146.82.138.56) by sources.redhat.com with SMTP; 21 May 2003 16:58:22 -0000 Received: from nevyn.them.org ([66.93.61.169] ident=mail) by crack.them.org with asmtp (Exim 3.12 #1 (Debian)) id 19IWvU-0008VV-00; Wed, 21 May 2003 11:58:52 -0500 Received: from drow by nevyn.them.org with local (Exim 3.36 #1 (Debian)) id 19IWuv-0002IR-00; Wed, 21 May 2003 12:58:17 -0400 Date: Wed, 21 May 2003 16:58:00 -0000 From: Daniel Jacobowitz To: Andrew Cagney Cc: cgd@broadcom.com, kevinb@redhat.com, gdb-patches@sources.redhat.com Subject: Re: [WIP/RFC] MIPS registers overhaul Message-ID: <20030521165816.GA8784@nevyn.them.org> Mail-Followup-To: Andrew Cagney , cgd@broadcom.com, kevinb@redhat.com, gdb-patches@sources.redhat.com References: <1030517004052.ZM13153@localhost.localdomain> <3ECA9587.4090407@redhat.com> <3ECB9C8F.1060706@redhat.com> <20030521154134.GA7667@nevyn.them.org> <3ECBA393.9020904@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <3ECBA393.9020904@redhat.com> User-Agent: Mutt/1.5.1i X-SW-Source: 2003-05/txt/msg00390.txt.bz2 On Wed, May 21, 2003 at 12:04:35PM -0400, Andrew Cagney wrote: > > >>That came out wrong. > >> > >>I think a GDB debugging a remote 64 bit MIPS ISA should always expect 64 > >>bit GPRs and 64 bit FPRs when the ISA is 64 bits, regardless of the ABI. > >> > >>It is quite legitimate, for instance, for GDB to do something as sick-o > >>as clearing the FR bit and then resume the thread. The register > >>save/restore code needs to correctly handle this - be it reject the > >>operation or ``do the right thing''. > > > > > >But when using rda or gdbserver to debug an o32 application, then for > >all intents and purposes we are debugging a 32-bit ISA. The kernel > >will not allow us to change the FR bit. The app will never see 64-bit > >registers. The 32-bit protocol makes more sense here IMO. > > From GDB's view point, the ISA is 64 bit. > > The fact that a specific remote debug agent choses to use 32 bit > registers is a limitation of that debug agent / kernel. An embedded > target, and I'm pretty sure IRIX 6.5, for instance, don't do that. No, from GDB's view point in this situation, the target ISA is _NOT_ 64 bit. Nothing 64-bit is available, either to the inferior or to the debugger. Period. I would be a little surprised if IRIX didn't work that way too, but I don't have access to IRIX to poke around. Certainly straight embedded is different. For those obviously the 64-bit protocol is appropriate. -- Daniel Jacobowitz MontaVista Software Debian GNU/Linux Developer